Related compounds
Solution A
Dilute 5.0 mL of perchloric acid in 900 mL of water, adjust with 2 M sodium hydroxide solution to a pH of 3.5, and dilute with water to 1000 mL.
Mobile phase
Prepare a filtered and degassed mixture of
Solution A, acetonitrile, and tetrahydrofuran (80:20:1). Make adjustments if necessary (see
System Suitability under
Chromatography
621
).
System suitability solution
Dissolve an accurately weighed quantity of
USP Alfuzosin System Suitability Mixture RS in
Mobile phase, and dilute quantitatively with
Mobile phase to obtain a solution containing about 0.4 mg per mL.
Test solution
Dissolve 40.0 mg of Alfuzosin Hydrochloride in Mobile phase, and dilute with Mobile phase to 100.0 mL.
Reference solution
Quantitatively dilute an accurately measured volume of the Test solution by a factor of 1000 with Mobile phase.
Chromatographic system (see Chromatography
621
)
The liquid chromatograph is equipped with a detector set at 254 nm and a 4.6-mm × 15-cm column that contains 5-µm packing L1. The flow rate is about 1.5 mL per minute. Chromatograph the
System suitability solution, and record the peak responses as directed for
Procedure: the peak-to-valley ratio is at least 5.
[NoteThe peak-to-valley ratio is determined as the ratio of the height above the baseline of the impurity A peak to the height above the baseline of the lowest point of the curve separating this impurity peak from the peak due to alfuzosin.
]
Procedure
Separately inject equal volumes (about 10 µL) of the
Reference solution and the
Test solution, record the chromatograms, and measure the peak responses. Calculate the percentage of each impurity in the portion of Alfuzosin Hydrochloride taken by the formula:
100[rU / (1000 rS)]
in which 100 is the percentage conversion factor;
rU is the peak response for any impurity obtained from the
Test solution; 1000 is the dilution factor; and
rS is the peak response for alfuzosin obtained from the
Reference solution: the limits are as shown in the accompanying table. Disregard any peak with an area less than 0.05%.
Compound |
Relative
Retention Time |
Limit
(%) |
Alfuzosin |
1.0 |
|
Impurity A1 |
1.2 |
* |
Impurity D2 |
0.5 |
0.20 |
Any individual unspecified impurity |
|
0.10 |
Total impurities |
|
0.30 |
1
N-[3-[(4-Amino-6,7-dimethoxyquinazolin-2-yl)(methyl)amino]propyl]furan-2-carboxamide.
2
N-(4-Amino-6,7-dimethoxyquinazolin-2-yl)-N-methylpropane-1,3-diamine.
|
Assay
Dissolve about 300 mg of Alfuzosin Hydrochloride, accurately weighed, in a mixture of 40 mL of anhydrous acetic acid and 40 mL of acetic anhydride. Titrate with 0.1 M perchloric acid, determining the endpoint potentiometrically. Each mL of 0.1 M perchloric acid is equivalent to 42.59 mg of C
19H
27N
5O
4·HCl.
USP32